In the present state of the art, illuminated signs are commonly constructed using rectangular sign boxes or cabinets. A sign box typically encloses a light source, such as a row of flourescent light tubes, that is mounted within the sign box. The sign box has one or more faces formed of translucent sheets that are mounted over the light source. Each face may be painted or marked with text or a design that is illuminated by the light source inside the sign box.
Sign boxes provide a weatherproof housing for the fluorescent light tubes, ballasts, wiring and other components in the sign. In many cases, the sign box is constructed using a framework of aluminum extrusions which form frame members and mounting components. The frame members and sign faces must be rigidly connected with one another to support the weight of the sign and withstand external forces, such as gale winds. At the same time, the frame members must allow access to the internal components of the sign so that the internal components can be serviced.
In many standard sign boxes, sign faces are bolted to the sign box frame. To service internal components in the sign box, the sign faces are disassembled from the frame to enable access to the sign box interior. Disassembly of a sign face requires effort and increases the overall time required to perform routine service on a sign installation. Accordingly, it is beneficial to provide an assembly for sign boxes to permit access to the interior of the sign box without requiring disassembly of the frame structure for the sign. One approach to solving this problem has been the use of sign boxes that have sign faces mounted to the frame on a piano hinge. Piano hinges allow a sign face to be pivoted to an open position without disassembling the frame. However, the piano hinge has been conventionally attached to both the frame and the sign face making complete removal of the sign face from the frame difficult. While it is nice to have a sign face that swings open, in certain applications, it would be even more desirable to have a sign face that has both the capability to be swung open and the capability to be easily detached from the frame. In still other applications, replacing the piano hinge for a more simplified hinge assembly creates a more cost effective design.